"Connecting Failed", my router and development build

[jcd2020 1]

Hi. I'm having tremendous problems joining any games on the development build. When trying to join any server, all I get is the "connecting failed" message after being taken back to the server list. This seems to only happen on the development build, I'm able to join most servers using the release build. After some googling and troubleshooting I determined that is somehow caused by my router, after removing it from the equation and connecting my pc straight to the cable modem I can connect any games freely. I tried disabling the firewall on my router (Asus RT-N16U), setting up port forwarding and triggering for ports 2302-2305 but it didn't fix anything...

Help please...